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 Oct17 comment Limit of a 0/0 function A hard requirement of the usability of l'Hôpital's rule is that the resulting "right-hand-size" is exists. But I guess that's what Hans is saying in more fancy terms? May12 comment How is the multiplicity of a pole defined when square roots are involved? Yes, of course, never cross the branch cut, but I'll need to calculate a limiting small circle integral around that point from one side of the cut to the other if I'm to avoid them, My question is more about that than the real residue which is defined differently for these points if it even exists. Dec9 comment Math question please ? Complex numbers? you need a $\pm$ instead of a $+$ in your second-to-last step. I can't edit such a small typo, hence the comment. Dec9 comment Solving a geometric algebra equation When you put it like that, it seems so simple... Thanks. Dec9 comment Solving a geometric algebra equation @GiuseppeNegro thanks for the additional reference. I'll be sure to check it out! Dec8 comment Solving a geometric algebra equation a,b, and c are vectors, $\alpha$ is a scalar. Juxtaposition is geometric product, dot is inner product. Dec3 comment How to simplify $\frac{4 + 2\sqrt6}{\sqrt{5 + 2\sqrt{6}}}$? Isn't this how you show 5 equals 4? Aug16 comment Is addition more fundamental than subtraction? @Lee: and a metric is positive by definition. Aug15 comment Is addition more fundamental than subtraction? @user1729 in my defense, I touched that aspect already in this comment Aug15 comment Is addition more fundamental than subtraction? A subtraction like this does not conform to the natural definition subtraction has. A metric is positive definite, subtraction is not. Aug14 comment Is addition more fundamental than subtraction? @AustinMohr: I'll keep that in mind. Sorry about that. Aug14 comment Is addition more fundamental than subtraction? @Drise: completely equivalent after the isomorphic transformation. So in Math speak: completely equivalent. Aug14 comment Is addition more fundamental than subtraction? Reversing the two concepts just leaves you with two isomorphic concepts that does not answer the question. Jul31 comment What's the meaning of the unit bivector i? @draks that is not geometric algebra. That's Dirac algebra which only makes sense in Dirac theory. Geometric algebra promises (I'm still learning) to be applicable/useful everywhere, not just in the case of $\gamma$s. And an index $i$ is nothing evil. Jul31 comment What's the meaning of the unit bivector i? @celtschk OK. But Hestenes maintains quaternions are just an aspect/transformation/... of the more general geometric algebra (at least in sofar they are used in Physics). I can't deduce any geometric meaning from quaternions either, so although insightful, it doesn't help me much (probably why you made it a comment anyways ;-)). Jul31 comment What's the meaning of the unit bivector i? OK. This is part of the meaning I get. The bivector as an operator is a rotor. But the bivector as basis element of the algebra should have a meaning on its own. Is my plane interpretation correct? Jul31 comment What's the meaning of the unit bivector i? It seems you avidly hate Hestenes' formulation. I get the parallel with $\gamma$ algebra the way you see it (I first came into contact with geometric algebra when studying the Dirac equation), but in the pdf referenced, he's not talking about $\gamma$ algebra, he's talking Euclidean geometry, where stuff like $\gamma$-matrices (he's not even talking about matrices) are not even relevant. You're giving a non-geometric interpretation IMHO, which is not quite what I'm after. I'm after the interpretation Hestenes describes. Jul30 comment What's the meaning of the unit bivector i? If someone would be so kind to tag this with a new tag geometric-algebra, I'd appreciate it. Nov9 comment Create list of {x,f(x)} pairs Funny how the (IMHO) much worse pops up in comments under my answer :) Nov7 comment A function of two functions that loses dependence on an argument Craig: see edit, my case here is really an addition of sorts, so no undefined things pop up.